High risk pregnancy: Small for date/large for date foetus) Flashcards
Whom to screen for gestational diabetes
- Asian/Afro Caribbean
- BMI>30
- Family history of DM in first degree relative
- Previous unexplained still birth
- Polyhydramnios and big baby
- Previous GDM
- Previous macrosomia >4.5kg
- Women with PCOS
- Glycosuria in 2 occasions in pregnancy
When to screen for gestational diabetes
• 26-28 weeks
At that time, Maximum placental function -> Human placental lactogen (HPL) secreted by placenta decreases maternal insulin sensitivity
Describe WHO- OGTT Test
- 75gms of glucose load
- Fasting blood sample, give 75gms of glucose and take sample after 2hours
- Fasting blood glucose >5.6mmol
- 2hour blood glucose > 7.8mmol
Management of suspected large baby in utero
- Big baby on palpation
- Refer for ultrasound
- If big baby on scan- do OGTT
- If abnormal OGTT-refer to diabetic team
- If normal OGTT, treat as normal pregnancy
Is C section indicated for Previous big baby?
- Previous severe shoulder dystocia- offer elective caesarean section
- Previous mild shoulder dystocia- treat as normal
Management of large-for-gestational-age pregnancy in non-diabetic women
BMI <30, favourable cervix induction of labour at 41 weeks
BMI >30, unfavourable cervix -> consider elective LSCS or induction of labour
Large for date Management of labour stage one
- Intravenous line/group and save
- Continuous CTG monitoring
- Adequate pan relief
- Regular cervical assessment
- Augmentation of labour if needed
Large for date Management of labour stage two
- Early recourse to caesarean section if no descent
- Senior midwife for delivery
- Obstetric registrar and consultant in attendance
Complications of shoulder dystocia: maternal
- PPH
* Trauma
Complications of shoulder dystocia: fetal
- Brachial plexus injury
- Asphyxia
- Erb’s palsy (C5,C6)
Large for date management: HELPERR
- Help (call for plenty)
- Evaluate for episiotomy
- Legs (McRoberts’ manoeuvre)
- Pressure (suprapubic)
- Enter (rotational manoeuvre)
- Remove the posterior arm
- Roll the patient onto her hands and knees.
Large for date Management of labour stage three
- Active management of third stage
- 40units syntocinon, 125/min
- Syntometrine (syntocinon 5 Units+ Ergometrine 500micrograms)
Definition of IUGR
SGA birth is defined as an estimated fetal weight (EFW) is less than the 10th centile for its gestation.
What is the most common cause of SGA foetuses?
50-70% of SGA fetuses are constitutionally small, based on Maternal size and ethnicity.
Differentials for symmetrical vs asymmetrical fetal growth restriction
Symmetrical: intrauterine infections, congenital anomalies, environmental factors
Assymetrical: pre-eclampsia, IUGR, smoking, Essential HTN
Pathophysiology of Asymmetric IUGR
- Fetus adjusts to inadequate nutrition
- Redistribution of blood flow
- More to heart, lungs and adrenal glands
- Less to liver and kidneys
- Abdominal circumference and fat stores are reduced more than the head.
- Brain sparing effect
Maternal behavioural factors that can cause fetal growth restriction
- Smoking
- Low booking weight (<50 kg)
- Poor nutrition
- Age <16 or >35 years at delivery
- Alcohol
- Drugs
- High altitude
- Social deprivation
- Maternal caffeine consumption ≥ 300 mg per day in the 3rd trimester
- Maternal exposure to domestic violence
- Low maternal weight gain
Maternal medical factors that can cause fetal growth restriction
- Chronic hypertension
- Connective tissue disease
- Severe chronic infection
- Diabetes mellitus
- Anaemia
- Uterine abnormalities
- Maternal malignancy
- Pre-eclampsia
- Thrombophilic defects
Fetal factors that can cause fetal growth restriction
- Multiple pregnancy
- Structural abnormality
- Chromosomal abnormalities
- Intrauterine (congenital) infection
- Inborn errors of metabolism
placental factors that can cause asymmetrical fetal growth restriction
- Impaired trophoblast invasion
- Partial abruption or infarction
- Chorioamnionitis
- Placental cysts
- Placenta praevia
Main pathology is impaired trophoblastic invasion leads to reduced perfusion in intervillous space.
Risks from IUGR
- Still birth
- Premature birth
- Fetal distress in labour
- 3-10 fold increase in perinatal mortality
- Neonatal unit admission
- Long term handicap
Conditions: necrotising enterocolitis, brain injury, respiratory distress, retinopathy
Major risk factors for IUGR
- Previous history of SGA or still birth
- Heavy smoking
- Cocaine abuse
- Heavy daily exercise
- Maternal illness –diabetes
- Parental SGA
Three key components of prevention of IUGR
- Aspirin (antiplatelet agent) from 16wks in women who are high risk for Pre-eclampsia and IUGR
- Smoking cessation
- Antithrombotic therapy in high risk women
Management of IUGR
Early onset: detailed scan, karyotype, screen for infections
Late onset: increased fetal surveillance, deliver early, steroids if <36 weeks
List 2 key components of Fetal Surveillance in IUGR
- Pregnancy associated plasma protein A (PAPPA)- low level indicates high risk for IUGR
- Maternal uterine artery doppler- 20-23weeks
- Abnormal wave forms and notch indicates high risk for IUGR
- Integrated screening for pregnancy risk- combining history/PAPPA/uterine artery doppler
- Pre-eclampsia/vagina bleeding/abdominal palpation –small for dates
How should Uterine Artery doppler scans be interpreted
Doppler can help identify cases of IUGR, or hypoxic and/or distressed fetuses. Changes occur in the umbilical artery waveform pattern obtained using Doppler ultrasound as placental resistance increases
- Uterine artery develops low resistance in pregnancy
- Presence of notch indicates high risk for IUGR /early onset pre-eclampsia and abruption.
- These women are given low dose Aspirin 75mg all through out pregnancy to prevent these complications
Uterine Artery doppler: Pulsatality Index (PI)
- Pulsatility index (PI) being the difference between peak systolic and end diastolic velocity divided by the mean velocity (PI = (Vmax - Vmin) / V mean).
- PI increases with increased placental resistance.
Management of IUGR < 34 weeks
- Gestation <34 weeks –aim is to prevent in utero demise or neurological damage
- Fetal weight should be > 500gms and the gestation > 25-26 weeks for gestation for fetus to be potentially viable.
- Umbilical artery doppler at least twice a week
- If doppler shows absent end diastolic flow – admitted for steroids
- If >32 weeks- delivery by LSCS
- IF <32 weeks- daily CTG and deliver if CTG abnormal
- Give magnesium prior to delivery
Management of IUGR 34 - 37 weeks gestation
delivery can be by induction or caesarean if CTG is abnormal.
Management of IUGR > 37 weeks gestation
delivery indicated by induction or caesarean if CTG is abnormal.
